<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
       /* visibility: hidden;   将元素隐藏 相当于透明度给0
          display: none;直接消失了
       */
        div{
         visibility: hidden;   
         /* display: none; */
        }
    </style>
</head>
<body>
    <div>hello world</div>
</body>
</html>